Recently, some electronic apparatuses (e.g. watches, mobile phones, and the like) are designed to have an ultraviolet (UV) detecting function. Conventionally, the UV detecting function is implemented by equipping an electronic apparatus with a commercially available UV sensor, which is produced according to a gallium nitride (GaN) fabricating process (as is disclosed in Japanese Patent Application No. JP-A-2005-69843 for example).
However, after the additional UV sensor is assembled into the electronic apparatus, the fabricating cost of the electronic apparatus will rise because of the UV sensor. In addition, since the electronic apparatus is designed to retain a space for assembling the UV sensor, the layout space of the electronic apparatus is stringently restricted. Therefore, it is necessary to obviate the above drawbacks.